The present invention relates to protective devices for ventilators and more specifically to a shroud for roof ventilators.
The present invention also represents a substantial improvement over previous methods of protecting roof ventilators and preventing heat loss.
Free flow roof turbines or ventilators are commonly utilized to inexpensively exhaust dormant hot air from attics or other space under a roofed area. They are also used to evacuate warm air from such areas as kitchens or laundries.
Roof ventilators are generally constructed of a plurality of curvilinear blades supported in a freely rotatable frame. The blades are contoured and oriented in relation to one another such that warm air rising from below, passes through the blades and due to the blade orientation, urges the blades and consequently the frame to rotate and expel the warm air.
This principle, although very effective in the summer months, was equally effective, but undesirable, in the winter months due to the significant heat losses in the winter. Heat generally escapes from homes during cold weather but the additional heat loss caused by heat being expelled from a home by the roof ventilator is costly and efforts to prevent heat loss are somewhat less than effective.
For example, one attempt to prevent heat loss was to cover the ventilator with a plastic bag which was tied at the bottom. Although generally very effective, the bags were usually destroyed by severe winds which are common in the winter. It therefore becomes necessary to replace the covering and to accomplish this, one had to climb to the roof. This operation would be repeated as often as the covering was destroyed which may be several times during the winter.
The applicant's device overcomes the disadvantages of previous attempts to reduce heat loss in that it is a durable ventilator covering that can be easily installed and removed; it will not require replacement; and minimizes the hazards of climbing the roof during severe weather.